Is there a way to implement this C macro in Go?

[sq...@google.com]

I've used this macro or some variant thereof in C/C++ for years:

  #define dump(x) printf("%s %d: %s = %d\n", __func__, __LINE__, #x, (int)(x))

The "#x" is the really useful part that lets you print the original expression. For example, if int a = 4 and int b = 10:

  dump(a + b);  // Prints "a + b = 14"

Is there a way to do this in Go? 

[Sam Whited]

On Thu, Jul 21, 2016 at 7:09 PM, sque via golang-nuts
<golan...@googlegroups.com> wrote:
> The "#x" is the really useful part that lets you print the original
> expression. For example, if int a = 4 and int b = 10

This is not exactly the same, but %#v is probably what you want:

https://godoc.org/fmt#hdr-Printing

—Sam


--
Sam Whited
pub 4096R/54083AE104EA7AD3

[Matt Harden]

No, there's no way to do that in Go. There is no preprocessor nor any other way to obtain the original expression. You'll have to duplicate the expression as part of your format string.

--
You received this message because you are subscribed to the Google Groups "golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Val]

This code "does the trick" (except in Playground) :

https://play.golang.org/p/kJAfNFZUev

$ go run macro.go
dump(a + b) = 14
dump(b * a) = 40

$ go build -o macro
$ ./macro
dump(a + b) = 14
dump(b * a) = 40

Read current stacktrace, extract source file path, read source file, extract textual (uncompiled) expression.

Disclaimer : I have no idea what I'm talking about